The following relates generally to wireless communication and more specifically to flexible time division duplexing (TDD) subframe structures with latency reduction.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems. A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
Wireless multiple-access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is Long Term Evolution (LTE). LTE is designed to improve spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards. LTE may use OFDMA on the downlink (DL), single-carrier frequency division multiple access (SC-FDMA) on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology.
In some cases, a wireless network may use TDD operations to accommodate both uplink and downlink communications using the same frequency spectrum. For example, a base station may select a radio frame configuration in which each subframe is designated as an uplink subframe, a downlink subframe, or a special subframe (i.e., a transition subframe between uplink and downlink subframes). However, designating an entire subframe for uplink or downlink may result in significant round trip latency. This may restrict the throughput or responsiveness of a communication network.